<linux就该这么学>第七章 RAID与LVM磁盘阵列技术
通过RAID和LVM可以更灵活的使用硬盘.
RAID阵列
不同阵列的对比:
raid0
raid0用来提高磁盘的读写速度,使用时从,多块硬盘中同时读写不同的数据,不具备有数据冗余备份的功能
raid1
raid1用来做数据的备份,将相同的数据写入多个硬盘中,当一块硬盘出现问题时,数据不会丢失.
raid5
raid5最少由三块硬盘组成,没块硬盘中,都存在数据块或者数据块对应的奇偶校验信息,切至少由一个硬盘中存在奇偶校验信息.因此raid5中允许一块硬盘损坏.
raid5的数据存储及校验计算
当一块硬盘损坏,使用一块新的硬盘取代损坏硬盘时:
RAID5校验位算法原理
P=D1 xor D2 xor D3 … xor Dn （D1,D2,D3 … Dn为数据块，P为校验，xor为异或运算）
XOR(Exclusive OR)的校验原理如下表：
tip:
随着硬盘数量和单个硬盘容量的增加,raid5的数据恢复成功率会降低,因此实际生产中也很少用
### raid10
raid10至少需要4块硬盘,其中两块一块用来组成raid1,再将两组raid1组成raid0,
tip:
对于raid01来说,如果两边同时有盘坏掉,则数据就会丢失,再安全性上不如raid10.
RAID10阵列的部署
raid阵列的命名,模式使用md开头
首先,需要给虚拟机添加4块硬盘.
# 组成阵列
mdadm -Cv {自定义的阵列设备名称} -n {磁盘数量} -l {阵列类型} {多个磁盘设备名称...}
# 查看状态
mdadm -D {阵列设备名称}
>>>
[root@localhost dev]# ls | grep ^sd
sda
sdb
sdc
sdd
# 创建磁盘阵列
[root@localhost dev]# mdadm -Cv /dev/md0 -n 4 -l 10 /dev/sd[a-d]
mdadm: layout defaults to n2
mdadm: layout defaults to n2
mdadm: chunk size defaults to 512K
mdadm: size set to 5237760K
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.
[root@localhost dev]# ls md0
md0
# 查看摘要
[root@localhost dev]# mdadm -Q /dev/md0
/dev/md0: 9.99GiB raid10 4 devices, 0 spares. Use mdadm --detail for more detail.
# 格式化
[root@localhost dev]# mkfs.xfs /dev/md0
meta-data=/dev/md0 isize=512 agcount=16, agsize=163712 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=1
data = bsize=4096 blocks=2618880, imaxpct=25
= sunit=128 swidth=256 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@localhost dev]# mkdir /myraid10
[root@localhost dev]# mount /dev/md0 /myraid10
[root@localhost dev]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 969M 0 969M 0% /dev
tmpfs 984M 0 984M 0% /dev/shm
tmpfs 984M 18M 966M 2% /run
tmpfs 984M 0 984M 0% /sys/fs/cgroup
/dev/mapper/rhel-root 17G 3.9G 14G 23% /
/dev/nvme0n1p1 1014M 152M 863M 15% /boot
tmpfs 197M 20K 197M 1% /run/user/42
tmpfs 197M 3.5M 194M 2% /run/user/1000
/dev/sr0 6.7G 6.7G 0 100% /run/media/linuxprobe/RHEL-8-0-0-BaseOS-x86_64
/dev/md0 10G 105M 9.9G 2% /myraid10
[root@localhost dev]# mdadm -D /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Wed Feb 17 23:10:13 2021
Raid Level : raid10
Array Size : 10475520 (9.99 GiB 10.73 GB)
Used Dev Size : 5237760 (5.00 GiB 5.36 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent
Update Time : Wed Feb 17 23:12:44 2021
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0
Layout : near=2
Chunk Size : 512K
Consistency Policy : resync
Name : localhost.localdomain:0 (local to host localhost.localdomain)
UUID : 12f52dd8:4c558aa8:fc3814be:070dde0e
Events : 17
Number Major Minor RaidDevice State
0 8 0 0 active sync set-A /dev/sda
1 8 16 1 active sync set-B /dev/sdb
2 8 32 2 active sync set-A /dev/sdc
3 8 48 3 active sync set-B /dev/sdd
# 持久化挂载
[root@localhost dev]# echo "/dev/md0 /myraid10 xfs defaults 0 0" >> /etc/fstab
[root@localhost dev]# mount -amdadm 命令的常用参数
RAID5及热备盘的部署
# 单独添加热备盘的方式
mdadm {raid设备名} -a {需要添加的设备路径}
>>>
# 3快组raid5，一块做热备盘
[root@localhost dev]# mdadm -Cv /dev/md0 -n 3 -l 5 -x 1 /dev/sd[a-d]
mdadm: layout defaults to left-symmetric
mdadm: layout defaults to left-symmetric
mdadm: chunk size defaults to 512K
mdadm: size set to 5237760K
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.
# 查看状态
[root@localhost dev]# mdadm -D /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Thu Feb 18 23:47:51 2021
Raid Level : raid5
Array Size : 10475520 (9.99 GiB 10.73 GB)
Used Dev Size : 5237760 (5.00 GiB 5.36 GB)
Raid Devices : 3
Total Devices : 4
Persistence : Superblock is persistent
Update Time : Thu Feb 18 23:48:20 2021
State : clean
Active Devices : 3
Working Devices : 4
Failed Devices : 0
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 512K
Consistency Policy : resync
Name : localhost.localdomain:0 (local to host localhost.localdomain)
UUID : b6294f16:92e4c84c:45bb47b2:6fb30a4f
Events : 18
Number Major Minor RaidDevice State
0 8 0 0 active sync /dev/sda
1 8 16 1 active sync /dev/sdb
4 8 32 2 active sync /dev/sdc
3 8 48 - spare /dev/sdd
[root@localhost dev]# mkfs.ext4 /dev/md0
mke2fs 1.44.3 (10-July-2018)
Creating filesystem with 2618880 4k blocks and 655360 inodes
Filesystem UUID: 86d66a98-b7e1-4b95-a841-c6e1dd067a51
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Allocating group tables: done
Writing inode tables: done
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done
[root@localhost dev]# mkdir /myraid5
[root@localhost dev]# echo "/dev/md0 /myraid5 ext4 defaults 0 0" >> /etc/fstab
[root@localhost dev]# mount -a
[root@localhost dev]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 969M 0 969M 0% /dev
tmpfs 984M 0 984M 0% /dev/shm
tmpfs 984M 18M 966M 2% /run
tmpfs 984M 0 984M 0% /sys/fs/cgroup
/dev/mapper/rhel-root 17G 3.9G 14G 23% /
/dev/nvme0n1p1 1014M 152M 863M 15% /boot
tmpfs 197M 20K 197M 1% /run/user/42
tmpfs 197M 3.5M 194M 2% /run/user/1000
/dev/sr0 6.7G 6.7G 0 100% /run/media/linuxprobe/RHEL-8-0-0-BaseOS-x86_64
/dev/md0 9.8G 37M 9.3G 1% /myraid5
# 此处移除虚拟机中的一块硬盘sdc，sdd会自动重建
[root@localhost dev]# mdadm -D /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Thu Feb 18 23:47:51 2021
Raid Level : raid5
Array Size : 10475520 (9.99 GiB 10.73 GB)
Used Dev Size : 5237760 (5.00 GiB 5.36 GB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Thu Feb 18 23:51:57 2021
State : clean, degraded, recovering
Active Devices : 2
Working Devices : 3
Failed Devices : 0
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 512K
Consistency Policy : resync
Rebuild Status : 11% complete
Name : localhost.localdomain:0 (local to host localhost.localdomain)
UUID : b6294f16:92e4c84c:45bb47b2:6fb30a4f
Events : 21
Number Major Minor RaidDevice State
0 8 0 0 active sync /dev/sda
1 8 16 1 active sync /dev/sdb
3 8 48 2 spare rebuilding /dev/sdd
[root@localhost dev]# mdadm -D /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Thu Feb 18 23:47:51 2021
Raid Level : raid5
Array Size : 10475520 (9.99 GiB 10.73 GB)
Used Dev Size : 5237760 (5.00 GiB 5.36 GB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Thu Feb 18 23:52:02 2021
State : clean, degraded, recovering
Active Devices : 2
Working Devices : 3
Failed Devices : 0
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 512K
Consistency Policy : resync
Rebuild Status : 26% complete
Name : localhost.localdomain:0 (local to host localhost.localdomain)
UUID : b6294f16:92e4c84c:45bb47b2:6fb30a4f
Events : 24
Number Major Minor RaidDevice State
0 8 0 0 active sync /dev/sda
1 8 16 1 active sync /dev/sdb
3 8 48 2 spare rebuilding /dev/sdd
LVM技术的使用
lvm技术将多个物理硬盘组成一个抽象的硬盘，然后可以将其切割为多个逻辑硬盘。
lvm切割的硬盘一般使用ext4格式，xfs格式不支持缩容。
通过lvm可以灵活的对硬盘进行调整，但lvm没有备份功能，可以在raid上建lvm,但这样性能的损耗会比较大。
部署逻辑卷
#1. 让硬盘支持LVM技术
pvcreate {硬盘1} {硬盘2}
#2. 将硬盘添加到逻辑卷组中
vgcreate {卷组名称} {硬盘1} {硬盘2}
#3. 切割逻辑卷，切割好的逻辑卷路径为 /dev/{卷组名称}/{卷名称}
## -l 后使用基本单元的个数， vgdisplay中的 PE Size 即代表基本单元的大小
## -L 后使用容量的大小
lvcreate -n {逻辑卷名称} -l {基本单元的个数} {逻辑卷组名称}
#4. 将硬盘格式化，并挂载
>>>
[root@localhost dev]# pvcreate sda sdb
Physical volume "sda" successfully created.
Physical volume "sdb" successfully created.
[root@localhost dev]# vgcreate mylvm sda sdb
Volume group "mylvm" successfully created
[root@localhost dev]# vgdisplay
--- Volume group ---
VG Name rhel
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size <19.00 GiB
PE Size 4.00 MiB
Total PE 4863
Alloc PE / Size 4863 / <19.00 GiB
Free PE / Size 0 / 0
VG UUID cTKWWM-t7yh-r342-JkSD-2bPU-Wjf0-tRExs8
--- Volume group ---
VG Name mylvm
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 2
Act PV 2
VG Size 9.99 GiB
PE Size 4.00 MiB
Total PE 2558
Alloc PE / Size 0 / 0
Free PE / Size 2558 / 9.99 GiB
VG UUID AzUk8Y-x1Y1-wMEn-wgbk-Lqru-WAWM-0zK19A
[root@localhost dev]# lvcreate -n mylvm01 -L 10M mylvm
Rounding up size to full physical extent 12.00 MiB
Logical volume "mylvm01" created.
[root@localhost dev]# lvdisplay
--- Logical volume ---
LV Path /dev/rhel/swap
LV Name swap
VG Name rhel
LV UUID 1Ug78x-W3LQ-e6DK-lJc4-OyO2-Q9E3-YusxNX
LV Write Access read/write
LV Creation host, time localhost, 2021-01-04 03:37:52 +0800
LV Status available
# open 2
LV Size 2.00 GiB
Current LE 512
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:1
--- Logical volume ---
LV Path /dev/rhel/root
LV Name root
VG Name rhel
LV UUID SyF0lV-U0KX-uFq6-8fdc-6kWa-d23n-qnIhY1
LV Write Access read/write
LV Creation host, time localhost, 2021-01-04 03:37:53 +0800
LV Status available
# open 1
LV Size <17.00 GiB
Current LE 4351
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
--- Logical volume ---
LV Path /dev/mylvm/mylvm01
LV Name mylvm01
VG Name mylvm
LV UUID DxqLeJ-SQLP-aAi3-jEZc-7Oma-hdTY-vo9OAA
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2021-02-19 21:04:31 +0800
LV Status available
# open 0
LV Size 12.00 MiB
Current LE 3
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:2
[root@localhost /]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 969M 0 969M 0% /dev
tmpfs 984M 0 984M 0% /dev/shm
tmpfs 984M 18M 966M 2% /run
tmpfs 984M 0 984M 0% /sys/fs/cgroup
/dev/mapper/rhel-root 17G 3.9G 14G 23% /
/dev/nvme0n1p1 1014M 152M 863M 15% /boot
tmpfs 197M 20K 197M 1% /run/user/42
tmpfs 197M 3.5M 194M 2% /run/user/1000
/dev/sr0 6.7G 6.7G 0 100% /run/media/linuxprobe/RHEL-8-0-0-BaseOS-x86_64
[root@localhost /]# mkdir /mylvmdir01
[root@localhost /]# mkfs.ext4 /dev/mylvm/mylvm01
mke2fs 1.44.3 (10-July-2018)
Creating filesystem with 12288 1k blocks and 3072 inodes
Filesystem UUID: 3215ccc8-82ef-4b3a-9577-91cc03d86567
Superblock backups stored on blocks:
8193
Allocating group tables: done
Writing inode tables: done
Creating journal (1024 blocks): done
Writing superblocks and filesystem accounting information: done
[root@localhost /]# mount /dev/mylvm/mylvm01 /mylvmdir01/
[root@localhost /]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 969M 0 969M 0% /dev
tmpfs 984M 0 984M 0% /dev/shm
tmpfs 984M 18M 966M 2% /run
tmpfs 984M 0 984M 0% /sys/fs/cgroup
/dev/mapper/rhel-root 17G 3.9G 14G 23% /
/dev/nvme0n1p1 1014M 152M 863M 15% /boot
tmpfs 197M 20K 197M 1% /run/user/42
tmpfs 197M 3.5M 194M 2% /run/user/1000
/dev/sr0 6.7G 6.7G 0 100% /run/media/linuxprobe/RHEL-8-0-0-BaseOS-x86_64
/dev/mapper/mylvm-mylvm01 11M 204K 9.6M 3% /mylvmdir01扩容逻辑卷
扩容时，需要先卸载挂载点，防止在扩容时有数据被写入，导致数据丢失。
# 1. 卸载挂载点
umount {设备|硬盘}
# 2. 扩容
lvextend -L {扩容后的容量} {卷名称}
# 3. 检查硬盘的完整性
e2fsck -f {卷名称}
# 4. 重置硬盘容量（通知系统）
resize2fs -f {卷名称}
# 5. 重新挂载硬盘
mount {设备} {目录}
>>>
[root@localhost /]# umount /mylvmdir01
[root@localhost /]# lvextend -l 5 /dev/mylvm/mylvm01
Size of logical volume mylvm/mylvm01 changed from 12.00 MiB (3 extents) to 20.00 MiB (5 extents).
Logical volume mylvm/mylvm01 successfully resized.
[root@localhost /]# lvdisplay
--- Logical volume ---
LV Path /dev/rhel/swap
LV Name swap
VG Name rhel
LV UUID 1Ug78x-W3LQ-e6DK-lJc4-OyO2-Q9E3-YusxNX
LV Write Access read/write
LV Creation host, time localhost, 2021-01-04 03:37:52 +0800
LV Status available
# open 2
LV Size 2.00 GiB
Current LE 512
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:1
--- Logical volume ---
LV Path /dev/rhel/root
LV Name root
VG Name rhel
LV UUID SyF0lV-U0KX-uFq6-8fdc-6kWa-d23n-qnIhY1
LV Write Access read/write
LV Creation host, time localhost, 2021-01-04 03:37:53 +0800
LV Status available
# open 1
LV Size <17.00 GiB
Current LE 4351
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
--- Logical volume ---
LV Path /dev/mylvm/mylvm01
LV Name mylvm01
VG Name mylvm
LV UUID DxqLeJ-SQLP-aAi3-jEZc-7Oma-hdTY-vo9OAA
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2021-02-19 21:04:31 +0800
LV Status available
# open 0
LV Size 20.00 MiB
Current LE 5
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:2
[root@localhost /]# e2fsck -f /dev/mylvm/mylvm01
e2fsck 1.44.3 (10-July-2018)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/mylvm/mylvm01: 11/3072 files (0.0% non-contiguous), 1621/12288 blocks
[root@localhost /]# resize2fs /dev/mylvm/mylvm01
resize2fs 1.44.3 (10-July-2018)
Resizing the filesystem on /dev/mylvm/mylvm01 to 20480 (1k) blocks.
The filesystem on /dev/mylvm/mylvm01 is now 20480 (1k) blocks long.
[root@localhost /]# mount /dev/mylvm/mylvm01 /mylvmdir01/
[root@localhost /]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 969M 0 969M 0% /dev
tmpfs 984M 0 984M 0% /dev/shm
tmpfs 984M 18M 966M 2% /run
tmpfs 984M 0 984M 0% /sys/fs/cgroup
/dev/mapper/rhel-root 17G 3.9G 14G 23% /
/dev/nvme0n1p1 1014M 152M 863M 15% /boot
tmpfs 197M 20K 197M 1% /run/user/42
tmpfs 197M 3.5M 194M 2% /run/user/1000
/dev/sr0 6.7G 6.7G 0 100% /run/media/linuxprobe/RHEL-8-0-0-BaseOS-x86_64
/dev/mapper/mylvm-mylvm01 19M 204K 17M 2% /mylvmdir01
缩小逻辑卷
缩小时更容易丢失数据，因此需要先检查完整性，如果出现错误则需要修复后再进行。
# 1. 卸载
# 2. 检查完整性
# 3. 重置硬盘容量
resize2fs {逻辑卷} {容量}
# 4. 缩容
lvreduce -L {容量} {逻辑卷}
# 5. 挂载
>>>
[root@localhost /]# umount /mylvmdir01
[root@localhost /]# e2fsck -f /dev/mylvm/mylvm01
e2fsck 1.44.3 (10-July-2018)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/mylvm/mylvm01: 11/4608 files (0.0% non-contiguous), 1815/20480 blocks
[root@localhost /]# resize2f /dev/mylvm/mylvm01 15M
bash: resize2f: command not found...
Failed to search for file: Cannot update read-only repo
[root@localhost /]# resize2fs /dev/mylvm/mylvm01 15M
resize2fs 1.44.3 (10-July-2018)
Resizing the filesystem on /dev/mylvm/mylvm01 to 15360 (1k) blocks.
The filesystem on /dev/mylvm/mylvm01 is now 15360 (1k) blocks long.
[root@localhost /]# lvreduce -L 15M /dev/mylvm/mylvm01
Rounding size to boundary between physical extents: 16.00 MiB.
WARNING: Reducing active logical volume to 16.00 MiB.
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce mylvm/mylvm01? [y/n]: y
Size of logical volume mylvm/mylvm01 changed from 20.00 MiB (5 extents) to 16.00 MiB (4 extents).
Logical volume mylvm/mylvm01 successfully resized.
[root@localhost /]# mount /dev/mylvm/mylvm01 /mylvmdir01/
[root@localhost /]# df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 969M 0 969M 0% /dev
tmpfs 984M 0 984M 0% /dev/shm
tmpfs 984M 18M 966M 2% /run
tmpfs 984M 0 984M 0% /sys/fs/cgroup
/dev/mapper/rhel-root 17G 3.9G 14G 23% /
/dev/nvme0n1p1 1014M 152M 863M 15% /boot
tmpfs 197M 20K 197M 1% /run/user/42
tmpfs 197M 3.5M 194M 2% /run/user/1000
/dev/sr0 6.7G 6.7G 0 100% /run/media/linuxprobe/RHEL-8-0-0-BaseOS-x86_64
/dev/mapper/mylvm-mylvm01 14M 204K 13M 2% /mylvmdir01
逻辑卷快照
使用逻辑卷快照，可以备份当前逻辑卷的状态，需要注意：
快照卷的容量需要与逻辑卷容量相同
快照卷仅一次有效，恢复后则会被立即删除。
# 1. 创建快照
lvcreate -L {容量} -s -n {快照名称} {逻辑卷名称}
# 2. 卸载目录
# 3. 恢复快照
lvconvert --merge {快照名称}
>>>
[root@localhost /]# cd /mylvmdir01/
[root@localhost mylvmdir01]# ls
lost+found
[root@localhost mylvmdir01]# echo "1" >> a.txt
[root@localhost mylvmdir01]# echo "1" >> b.txt
[root@localhost mylvmdir01]# lvcreate -L 16M -s -n mybackup /dev/mylvm/mylvm01
Logical volume "mybackup" created.
[root@localhost mylvmdir01]# echo "2" >> c.txt
[root@localhost mylvmdir01]# ls
a.txt b.txt c.txt lost+found
[root@localhost mylvmdir01]# cd /
[root@localhost /]# umount /mylvmdir01
[root@localhost /]# lvconvert --merge /dev/mylvm/mybackup
Merging of volume mylvm/mybackup started.
mylvm/mylvm01: Merged: 100.00%
[root@localhost mylvmdir01]# mount /dev/mylvm/mylvm01 /mylvmdir01/
[root@localhost mylvmdir01]# ls
a.txt b.txt
[root@localhost /]# cd /mylvmdir01/
[root@localhost mylvmdir01]# ls
a.txt b.txt
删除逻辑卷
# 1. 卸载目录（如果已经卸载则不需要）
# 2. 删除逻辑卷设备
lvremove {逻辑卷名称}
# 3. 删除卷组
vgremove {逻辑卷组名称}
# 4. 删除物理卷设备
pvremove {设备1} {设备2}
>>>
[root@localhost mylvmdir01]# umount /mylvmdir01
[root@localhost mylvmdir01]# lvremove /dev/mylvm/mylvm01
Do you really want to remove active logical volume mylvm/mylvm01? [y/n]: y
Logical volume "mylvm01" successfully removed
[root@localhost mylvmdir01]# vgremove /dev/mylvm
Volume group "mylvm" successfully removed
[root@localhost mylvmdir01]# pvremove /dev/sd[a-b]
Labels on physical volume "/dev/sda" successfully wiped.
Labels on physical volume "/dev/sdb" successfully wiped.
License:
CC BY 4.0